FIX:Replaced pytz with Zoneinfo because it is an efficient and modular wa…

[NandanaRaol]

This pull request refactors the handling of time zones in the mssql package by replacing the pytz library with Python's standard library zoneinfo module. Additionally, it updates the test suite to reflect these changes and removes pytz from the package dependencies.

Time zone handling updates:

• Replaced the pytz library with the zoneinfo module for time zone operations in mssql/operations.py, including updates to the _get_utcoffset method to use ZoneInfo for calculating UTC offsets. [1] [2]

Dependency updates:

• Removed pytz from the install_requires list in setup.py, as it is no longer required.

Test suite updates:

• Updated testapp/tests/test_timezones.py to import and use ZoneInfo. Added a new TestGetUTCOffset test class to validate the _get_utcoffset method with various time zones. [1] [2]